Boeing has completed aeroelastic flutter testing and ground effects testing with its first two 787 test aircraft. This clears the way for the formal US Federal Aviation Administration certification campaign to begin to support the target of delivering the first aircraft this year.
Dreamliner ZA001 completed flutter testing on 19 March after 27 test days that began on 14 February and saw the aircraft reach a ceiling of 43,000ft (13,100m) while maintaining a cabin pressure of 6,000ft. Additionally, the aircraft reached Mach 0.97 in a dive as part of clearing the primarily carbonfibre structure of any potentially destructive vibration.
"The technical team has made an initial assessment of the data and we couldn't be more pleased with the performance of the 787," says Boeing vice-president of marketing Randy Tinseth. The damping was as predicted and the pilots report that the airplane responded as expected."
Tinseth adds that the 787 test fleet is now cleared to fly throughout its full flight envelope.
Additionally ZA002 completed ground effects testing on 19 March in Victorville, California. The 787 was used to evaluate the handling characteristics of the aircraft in take-off and landing phases of flight.
ZA004, which returned to flight testing on 18 March, has been testing the latest "service-ready" V5.5 system software in preparation for presentation of a conforming article to the FAA for type inspection authorisation.
Boeing aims to test the wing of the 787 static test airframe to its ultimate load on 28 March. During the test, the wing of "ZY997" will be slowly flexed to 150% of the design limit load as part of the structural testing of the primary composite structure. However, Boeing does not intend to flex beyond 150% to the point of destruction, as with previous tests.
Source: Flight International